Interface implemented by server-side request objects, to allow
routing/dispatching of requests based on information from path
and related target metadata.
Note that all values are handled as-is, without doing any URL decoded (or
encoding).

Method for returning current remaning path (not including
parts that have been removed with nextPathSegment());
and without additional URL decoding (but may have been decoded,
as per getDecodedPath()).
Usually used to be able to later on reset path with setPath().

Method for checking that the next path segment (as returned by
nextPathSegment()) would match given segment; and if so,
remove the segment and return true. Otherwise returns null
and leaves path unchanged.